Applied Materials, Inc.

Andrew Holmes

Jonathan Gerald England

David George Armour

Stephen Moffatt

Amir Hamed Al-Bayati

Adrian John Murrell

Bernard F Harrison

Paul A Burfield

Simon Herbert Povall

Drew Arnold

Erik Jan Hilda Collart

Chris James Burgess

Jaap Van Den Berg

An ion beam generation apparatus comprising an ion source ( ) for generating ions, and a tetrode extraction assembly ( ) comprising four electrodes for extracting and accelerating ions from the ion source. The extraction assembly comprises a source electrode ( ) at the potential of the ion source, an extraction electrode ( ) adjacent to the source electrode to extract ions from the ion source ( ), a ground electrode ( ), and a suppression electrode ( ) between the extraction electrode and the ground electrode. Each electrode has an aperture to allow the ion beam to pass therethrough. The gap between the extraction ( ) and suppression ( ) electrodes is variable in the direction of ion beam travel.

Ion beam generation apparatus

A source of thermionic electrons is provided inside the flight tube of a magnet, especially an analysing magnet, and extends along the beam flight path. This allows space charge to be neutralised along the beam's axis in spite of severely restricted electron mobility in this direction owing to the presence of substantially transverse magnetic field. Thermionically emitted electrons may contribute directly to the neutralisation of space charge in positive ion beams, or, in the case of negative ion beams, indirectly by ionizing residual or deliberately introduced neutral gas atoms or molecules. Examples are described and claimed in which the source is arranged outside the nominal beam envelope in the flight tube, but linked to the beam by magnetic flux generated in the flight tube. This reduces erosion of the source by the beam and so reduces beam contamination. In these examples, an important feature is the provision of electron repellers to reflect electrons back and forth across the beam. Alternative arrangements are described and claimed in which the source is positioned inside the beam. The thermionic electron source may comprise an array of filaments, and preferably is negatively biased with respect to the flight tube. Adjustment of this bias enables the energy of emitted electrons to be controlled.

Ion beam apparatus and a method for neutralizing space charge in an ion beam

An ion implanter for implanting ions in a target substrate is arranged to scan the ion beam at the point of extraction of the beam from the ion source. The ion beam extraction assembly includes a tectrode construction in which an extraction electrode adjacent the ion source aperture is split into two halves. A differential voltage is applied across the two halves of the extraction electrode to deflect the ion beam being extracted from the ion source electrostatically. The plane of deflection is arranged to coincide with the plane if dispersion of the ions in a mass analyser magnet downstream of the extraction point and the deflected beam of ions of desired mass/charge ratio is still brought to focus at a common mass selection slit at the exit of the analyser magnet.

Method and apparatus for ion beam scanning in an ion implanter

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Oxon, United Kingdom

Andrew Holmes